can not deactivate license due to the message "No valid license found. Do you want to buy or install

I activated the license for ReadyApi1.9.0 on 10/27/2017, a day later after launched the app got: "No valid license found. Do you want to buy or install a license?" message. I installed the license again but still got the message. 

Uninstalled ReadyApi1.9.0 and reinstalled it, was asked to deactivate the license installed previously, but the pop up message "No valid license found. Do you want to buy or install a license?" prevented clicking Help button to deactivate the license. Please advise.  Thanks.